package simpledemo;

public abstract class Duck {
	IFly fly=null;
	IQuack quack=null;
	
	public void swimming(){
		System.out.println("I can swiming");
	}
	public abstract void display();
	
	public void peformFly(){
		fly.fly();
	}
	public void performQuack(){
		quack.quack();
	}
}
